Demountable clock



Nov. 17, 1931. E. L. CARLSON DEMOUNTABLE CLOCK Filed June 19. 1929 Patented Nov. 17, 1931 UNITED STATES PATENT OFFICE ELOF L. CARLSON, OF BRISTOL, CONNECTICUT, ASSIGNOR TO THE E. INGBAHAM CO., 015 BRISTOL, CONNECTICUT, A CORPORATION DEMOUNTABLE CLOCK Application filed June 19,

This invention relates to an improvement in demountable clocks of the well-known type in which a separately-organized movementunit is held in a clock-case by friction so as to be readily demounted and mounted to permit the convenient interchange of standard movements and cases, in order that various combinations of form, color, etc., may be made by a retailer to meet the taste of his trade.

The main object of this invention is to provide a demountable clock of the class de scribed in which the slight variations and unavoidable inaccuracies incident to manufacture on a commercial scale wiil be compensated for in advance and not interfere with the successful mounting and demounting of movement-units with respect to their cases.

Another object of this invention is to provide a demountable clock characterized as above and having superior resistance to relative rotary movement between the movement and case-units when assembled so that the winding of the clock and other rotary strains will not displace the parts.

WVith the above and other objects in view, my invention consists in a demountable clock having certain details of construction and combinations of parts as will be hereinafter clock constructed in accordance with our invention;

Fig. 2 is a view showing the case-unit in transverse section and the movement-unit in edge elevation;

Fig. 3 is a view corresponding to Fig. 2 but showing the shell and positioning-plate of the movement-unit in section;

Fig. 4 is a view of my improved demountable clock in rear elevation;

Fig. 5 is a detachable perspective view of the positioning-plate, together with its in tegral arched positioning-bows;

Fig. 6 is a transverse sectional view corresponding to Fig. 3, but showing a modified 1929. Serial No. 372,204.

form of movement-unit installed in a clockcase;

Fig. '4' is a view thereof in vertical section on the line 7 7 of Fig. 6; and

Fig. 8 is a detached perspective view of the cupshaped dust-guard or shell thereof.

In carrying out my invention as shown in Figs. 1 to 5 inclusive, I employ a movementunit comprising a movement-housing 10 enclosing a time-movement (not shown) of any approved form, and provided at its front end with an overhanging bezel 11 mounting the usual convex crystal 12 and adapted to bear against the front face of a clock-case 13, as will hereinafter appear.

The movement-housing 10 is formed, as shown, with an annular step 14 larger in diameter than the main portion of the said housing and smaller in diameter than the diameter of the bezei 11. The step 14 of the housing 10 has sleeved over it the forward open end of the tubular portion 15 of a sheet-metal cup-shaped shell or dust-guard 16, the rearwall 17 of which is formed with openings 18 and 19 for the clearance, respectively, of the winding-arbor 20 and the setting-arbor 21 of the movement enclosed within the housing 10 before referred to.

The housing 10 and the shell 16 are held together so as to form a unitary element by pillars 22 which extend through the rear wall 17 of the said shell and also through a positioning-plate 23 bearing against the rear face of the said shell, as clearly shown in Fig. 3 of the drawings. The outer end of each of the pillars 22 aforesaid is threaded in the usual manner for the reception of a nut 24: which, when tightened, serves to clamp the positioning-plate 23 to the back of the shell 16 and engage the forward edge of the tubular portion 15 of the shell 16 with the rear face of the bezel 11.

From the foregoing it will be seen that the housing 10, bezel 11, crystal 12, shell 16 and positioning-plate 28, as well as the attached part-s, are organized as a unit.

At four equidistant points the positioning plate 23 has formed upon its periphery four (more or less) resilient positioning-bows 25 which extend forward from the said plate in P a direction substantially parallel with the axis of the movement-unit and are adapted to have their free forward ends rest upon the periphery of the tubular portion 15 of the shell 16, as clearly shown in Figs. 2 and 3 of the drawings.

The clock-case 13 before referred to may be of any approved type and as herein shownris of solid material, such as Wood, and is formed with a tubular socket 26 extending from front to rear therethrough, slightly larger in diameter than the diameter of the shell 16 and proportioned so that when the movement-unit is installed it will serve; to cause the bows 25 to be slightly flattened and tensioned, so that the-movement-unit and the case-unit are firmly coupled against relative, rotary and axial displacement except; by a deliberate effort to displace them.

By virtue of, the arched character ofthe bows 25,- considerable variations in size of: the socket 26 or of the shell16 will not affect the successful retention ofthe movementunit in place. Furthermore, the relativelysharp edges of'the bows 25 will bite, 'so to speak, into the wall of'the socket 26 in the case 13 and so effectively prevent the rotation of the movement-unit with respect to the case-unit when rotary strains are. applied, such as duringthewindingoperation when the winding-arbor 20 is beingrotated.

In the formofmy invention illustrated in Figs, 6 to 8 inclusive, instead ofproviding a supplementalpositioning-plate 23 having bows 25, I cutthe tubular portion 15-of the shelllfito form four (more or less) equidistant pairs of slits and stretch the narrow band? of material lying-between each pair of slits outward to form integral bows 27" which havetheir sharp side-edges free of theshell but their ends remaining integral with the same. 7

I claim:

A movement-unit for demountable clocks comprising a cup-shaped shell, the flange of which is slitted and upset to produceaplurality of substantially-equidistant outwardly-projecting resilient integral positioning.- bows extending substantially-parallel with the axis of the shell and adapted to engage a case-unit foryieldingly holding themovement therein.

In testimony whereof, I havesigned this specification.

ELOF L. CARLSON; 

